Changing color of page titles

Hi. I am using the Sydney Pro theme and have been trying to change the color of the titles on each page of this website: ehrcommandcenter.com. After reading this forum and others, I tried the code suggestions below and none of them had any effect on this website.

    .hentry .title-post{
      color: #8B8B8C;
    }

    .page .entry-header .title-post {
      color: #8B8B8C;
    }

    .page .hentry .title-post {
      color: #66658a;  
    }  

Do you have another suggestion?

Hello there,

Did you section title color like “OUR TECHNOLOGY”, “LEARN MORE”, “INNOVATION FOR TODAY”? Please be more specific.

Regards,
Kharis